The idiopathic interstitial pneumonias (IIPs) represent a group of lung diseases commonly characterized by pulmonary fibrosis or progressive scarring of the alveolar interstitium which can lead to significant morbidity and mortality due to hypoxemic respiratory insufficiency. While some forms of pulmonary fibrosis are associated with known environmental exposures (e.g. asbestos), drug toxicity, radiation exposures, or collagen vascular diseases (e.g. scleroderma), the IIPs have no known etiology. The most common and severe IIP is idiopathic pulmonary fibrosis (IPF) which has a median survival of 2-3 years after diagnosis. There are no IPF pharmacologic therapies approved for use in the United States, and lung transplantation is the only intervention to prolong life. Although all IIPs have a variable clinical course, they often progress to end-stage lung disease and death. While it appears that the risk of IIP is likely determined by multiple genetic variants and environmental toxins, the causes of IIP are only beginning to emerge.
There is a need for identification of genetic variants, acting independently or in combination, that are indicative of different histologic types of interstitial lung diseases, as well as methods of identifying these genetic variants in an individual, diagnosed with, or suspected of being predisposed to the development of, interstitial lung disease. Provided herein are solutions to these and other problems in the art.